1. Field of the Invention
The present invention relates to medical devices designed to protect wounds of patients against outside forces accidentally coming in contact with the wounds. More particularly, the invention relates to dressings which protect incision wounds during the healing process.
2. Reported Developments
Serious skin wounds resulting from surgical incisions are sensitive to excessive pressure such as that produced by clothing worn by the patient. Such pressure is particularly dangerous when the wound is in an area where tight fitting clothing is often worn. Modern wound closing techniques are strong enough to withstand some light pressure on a bandaged wound if the pressure is evenly distributed, but strong and/or uneven pressure can cause pain, break the healing scab, pull or even break the sutures. An example of the later undesirable situation is the waistband of a pair of trousers running perpendicular to a vertical incision wound resulting from abdominal surgery.
In very serious, deep and irregular wounds such as large burned skin areas, or with surgical incisions pressure is so undesirable that protective devices have been invented by the prior art to keep clothing and foreign objects away from the wounded area. These devices are of two types, called herein Type I and Type II.
In Type I the devices contain rigid or semi-rigid rods or strips with supports that lift the rods or strips away from the wound in a direction perpendicular to the body surface. Examples are found in U.S. Pat. Nos. 3,976,066; 4,159,021; 4,000,737; and 2,520,436. These devices create an air pocket between the wound and the clothing, and are held in place by flexible straps or adhesive applied to the supports. The common characteristic of these devices is the presence of flat, foot-like endings to the strips or rods which transfer the pressure, for example from clothing or a sharp blow, from directionally perpendicular to the wound to the skin surrounding the wound at the fixed points where the feet contact the skin around the wound. This protects the wound from a direct, uneven pressure, reducing the magnitude of the pressure by dividing that pressure into the number of foot-like endings, and dissipating the pressure by transferring it to several points in the skin, more or less evenly around the wound.
Type II devices are found for example in U.S. Pat. Nos. 3,026,874; 2,367,690; 4,023,569; 2,663,020; 3,528,416; and 1,319,299. Here the pressure is again transferred away from the wound by creating an air space over the wound. Here the absorbed pressure is then further reduced in magnitude per skin contact point over Type I devices because pressure is transferred to more area of the skin in a continuous line or lines, for example a ring, or square surrounding the wound. In both types of devices, the attempt is to change perpendicular, uneven pressure directed at the wound to more even pressure of a lower magnitude by spreading it over a larger area and redirect it to the skin surrounding the wound.